[Surgical treatment of midshaft clavicular fractures using intramedullary nail].

Introduction: The aim of our study was to assess treatment outcomes in fractures of the middle part of the clavicle using an intramedullary nail.

Methods: We have evaluated a total of 58 patients with a clavicle bone fracture stabilized by the Hofer Clavicula Pin implant (HCP, Hofer GmbH & Co KG, Fürstenfeld, Germany). A static implant was used in 43 cases, and a dynamic implant was used in the remaining 15. The mean age of patients was 39.1 years (range 1871, SD 4.4), the male-to-female ratio being 43:15. The right collarbone was broken in 26 patients, the left one in 32. The average time between accident and surgery was 10.2 days (range 2-19, SD 4.4). The set included 24 two-, 14 three- and 20 four-fragment fractures of the clavicle midshaft. Open reduction was used in all the cases. The implant was introduced by the indirect method: first, insertion of the pin from the fracture antegrade into the lateral fragment took place, then it was inserted retrogradely into the medial fragment.

Results: The average patient follow-up was 7.1 months (range 623, SD 5.5). X-ray signs of healing were evident in all cases, with healing occurring at 8.4 weeks on average (range 620, SD 4.1). In one case (1.7%), however, healing did not occur - refracture was diagnosed 18 days following pin extraction with no clear mechanism of injury; two more refractures were caused by a new accident. The apex of the pin was broken in four cases (6.9%). In two cases (3.4%), angulation of the pin occurred; however, full fracture healing was satisfactorily achieved. Pin prominence was observed in a total of 23 cases (39.7%), requiring premature extraction of the implant due to perforation or irritation of skin and pain in 13 (22.4%) cases. 10 cases (17.2%) of prominence were asymptomatic. Six cases with skin perforation by the implant developed clinical signs of infection, wound healing was always achieved after extraction of the pin and application of antibiotics. A very good functional finding in the shoulder joint was observed in 57 patients (98.2%). The DASH score reached an average of 8.1 points (range 0.8-30.8, SD 4.4). Constant score was 93.1 (range 42.8-98.1, SD 3.2).

Conclusion: Intramedullary stabilization of two-, three- and four-fragment fractures of the middle part of the clavicle using the Hofer Clavicula Pin provides very good stability during healing and leads to good healing of fractures. The complications of the method are soft tissue irritation or even skin perforation in the region of the lateral end of the implant. Preventive insertion of the pin closer to the bone may prevent such complications, but also result in difficult pin extraction.Key words: fractures - clavicle - osteosynthesis - intramedullary complications.